JPS5999290A - Control device for reactor control rod - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

The present invention relates to a nuclear reactor control rod control device, and in particular, a control rod used for controlling the thermal output of a nuclear reactor and shutting down the reactor.
The present invention relates to a control device for a control rod drive mechanism used for insertion into or withdrawal from a nuclear reactor. FIG. 1 shows a simplified structure of a magnetic jack type drive mechanism for nuclear reactor control rods. In the figure, three coils, lift coil l, movable gripper coil (hereinafter referred to as MG coil) l, and stationary gripper coil (hereinafter referred to as SG coil) 3 installed outside the reactor pressure vessel, are atomic. Operate the excitation armature housed in the furnace pressure vessel. That is, a movable gripper armature l and a stationary gripper armature l.
The fan 1 operates latches 7 and t which engage the valleys or grooves 6a of the control rod drive mechanism when the M() coil coil and the SG coil 3, respectively, are energized. The stationary latch t is used to hold the control rod drive shaft 6 in a certain position. The movable latch 7 moves the lift armature when the lift coil l is energized.
It is used to prevent (move in the withdrawal direction) and lower (move in the insertion direction) the control rod drive shaft t. In addition, /a is the lift magnetic pole, 3a is the stationary gripper magnetic pole, and 7a is the stationary gripper armature.
is a movable latch link, and ga is a stationary latch link. FIG. 2 shows the operation sequence of the above-mentioned f-distance drive rod drive mechanism. In FIG. 1, corresponding parts in FIG. 1 are represented by the same reference numerals, but the movable latch 7 and the stationary latch g are shown in a simplified manner. The control rod withdrawal sequence and insertion sequence will be described below with reference to FIGS. 1 and 2. A: Withdrawal sequence (a) In the standby state, the Sa coil is energized and the stationary latch is closed to hold the control rod drive shaft. [Status of Figure 1 (a) - (B)] (B) M
() Excite the coil coil and close the movable latch 7. [States shown in FIGS. 2(a)-(b)] ()3 Demagnetize the SG coil 3 and release the stationary latch. [
Figure 2 (a) -H state) The lift coil 1 is energized to operate the lift armature and raise the movable gripper armature. As a result, the control rod drive shaft 6 supported by the movable latch is raised in the direction of the arrow by one groove 6a of the control rod drive shaft. [State shown in Figure 2 (a) -) (Energize the nsG coil and close the stationary latch. [State shown in Figure 1 (al-(E))] (Go) M
Demagnetize the G coil coil and release the movable latch 7. [State of FIG. 2 (a) = (to)] (g) Demagnetize the lift coil 1 and lower the lift armature 9 in the direction of the arrow. [Figure 1 (a) - (state of 3 (4/))] Repeat the operation from (fi OS) to (g). B: Insertion sequence (a) In the standby state, the SG coil 3 is not excited. , the stationary latch g is closed and holds the aerial control rod drive shaft t. [Status shown in Fig. 2 (b) - (a)] (b)
Excite the lift coil 1 to raise the lift armature in the direction of the arrow. [States in FIGS. 2(h)-(b)] ()) Excite the MG coil 2 and close the movable latch 7. [In the state of -H in Fig. 2(b)]) Demagnetize the 8G coil 3 and release the stationary latch. [Status shown in Fig. 2 (bl-)] (l) Demagnetize the lift coil l, lower the lift armature, and lower the movable gripper armature. Lower the stationary latch by one position in the direction of the arrow. [Status shown in Fig. 2 (b) - (e)] (f) Excite the SG coil 3 and close the stationary latch t. [Fig. 2 (b) - ( ) status] (g)
Demagnetize the MG coil λ to release the movable grid. [Figure 2 (state of bl -H)] (Example (b)
Repeat the steps from (g). As described above, control rods are inserted into or withdrawn from the reactor by sequentially supplying Q of direct current to three types of coils: SG coil, MG coil, and lift coil of the control rod drive mechanism. It is also held in a fixed position by driving the control rod Lfr and continuing to excite the SG coil. Here, when not driving the control rod (second
Figures (a) and (b)-(a)) show that the SG coil is excited and t

[It is important to note that if this were to happen, the control rods would fall into the reactor. The control rod controller supplies direct current to the seven types of coils in the control rod drive mechanism. Conventionally, there has been a device of this type as shown in FIG. In the figure, loads lθ, 2θ, and 3θ correspond to the three types of coils of the control rod drive mechanism described above. That is, the load lθ corresponds to the SG coil of the plurality of control rod drive mechanisms 419, the load setting θ corresponds to the MG coil of the plurality of control rod drive mechanisms, and the load 30 corresponds to the lift of the plurality of control rod drive mechanisms. Corresponds to a coil. Each load consists of a 3 bar load. That is, the first set of loads lθ consists of the SG coils of the first group/2, the third group lda, and the third group 16. These three groups lλ. 1ll and /6 loads all require a DC sequence at the same level (when the SG coil is excited to hold the control rods), and the control rods are driven sequentially by group, but control is possible even during periods when the control rods are not driven. K to hold the rod in a fixed position
Since the SG coils of all control rod drive mechanisms must be energized, they are not switched like the second and third sets of loads. Similarly, for the first set of loads 20, there are 2 loads in the 7th group and 2'l in the second group.
, and the third group consists of two MG coils. The loads in each of these three groups all still require the same level of DC sequence, but with different excitation periods. In other words, all three groups of control rods are driven, but their driving times are different. Therefore, the seventh group of control rods is driven by a first group control rod drive mechanism that includes a first group of SG coils, a seventh group of MG coils, and a (7) first group of lift coils. The second group control rods are driven by a group control rod drive mechanism that includes a second group SG coil, a MG coil, and a lift coil. Similarly, the third group control rods are driven by a third group control rod drive mechanism. As described above, the drive sequence for each group of control rods is performed by sequentially energizing the three types of coils of each control rod drive mechanism. The three-phase power is supplied by the three-phase power supply qo to a plurality of electric power units 11, 2, 4 (A, !l-θ, jλ and hee, !l-4'
supplied to This electric kaninit supplies DC output at predetermined multi-level (usually three levels) values based on a reference current signal from a reference current source, which will be described later. 1st Denkaninitz'
12 receives three-phase power from a three-phase power supply qθ through a single line illustrated as '%</. The first electric crab unit 11.2 is an electric crab unit for providing a DC sequence to the lift coils of a plurality of control rod drive mechanisms. The first output from the three-phase power source θ is fed to the first electrical unit (1) 4/B through the line g. The second power unit tog 6 is an electric power unit for providing direct current to the MG coils of a plurality of control rod drive mechanisms. From the third output lI9 from the three-phase power supply 9A, respectively, three separate electrical circuits so, ! Three-phase power is supplied to the rco and tag. Electric crab knit kO! ;
, 2 and q are the SGs of multiple control rod drive mechanisms, respectively.
It is an electrical knit for providing direct current to the coil in a predetermined sequence. Each load/2. /'I pumped 16 different electric crab knits on the left 0. ! ;2. The reason for providing these tags is that when a group of control rods is inserted or withdrawn during operation of the control rod drive device, the SG coils of the control rod drive mechanisms of the remaining control rod groups are energized and This is because it is necessary to hold the control rod in a fixed position. For example, if the first group control rod drive mechanism is to be energized, then the first group load (SG coil) of the first set/θ/2
, the load of the first group (M a coil) of the first coil θ, 72 and the third group, ? 0 7th group load (lift coil) 3.2
When energizing sequentially according to a predetermined DC sequence, the first
energizing the loads /41 and /l of the second, second and third groups of group /θ to prevent the control rods driven by these control rod drive mechanisms from falling into the reactor; This is because it is necessary. A, 2 usually has three levels: zero current value (current value that demagnetizes the coil), low limit current value (current value required to hold the control rod), and full current value (current value required to hold the control rod at Hayabusa This is a well-known reference current source that generates a reference current signal having a current value (current value required only when driving) in a predetermined sequence. DC is supplied to various loads from the The reference current source 62 sends a first reference current signal to the first electric power unit (1t=supply-t-) via a line t. A first reference current signal is used to adjust the DC output of the r
[The IR output is the load of the 1st group, 2nd group, and 3rd group,?
, 2.3Q and 3t, respectively, through lines qg, troR and g2. f, is selected by a switching circuit B6 (for example, one controlled by an external bank selection circuit). Similarly, a first reference current signal from the reference current sources 6 is supplied via a line 74t to a second power unit 14'4, which is an electric unit for MG coils of a plurality of control rod drive mechanisms. The DC output from the second electric crab unit llA is supplied to the second switching circuit 76, and the load saws 9 of the first group, second group and third group are .2g and: 6g of line to any one of 16. DC is supplied through 7θ and 72. The reference current source t2 supplies seven separate groups of third reference current signals to the third electric crab unit left O, octopus, and tag for the SG coil through the lines g9gt and gza, respectively (however, , all groups are supplied with a reference current signal of the same DC level in the holding state (13).A separate third reference current signal group is supplied to these three normal units (ti).The reason is that one group of This is because when a control rod is inserted or withdrawn, it is necessary to energize the SG coils of the control rod drive mechanisms of the remaining control rod groups to hold these control rods in a fixed position. Note that the first and first power units may be configured as thyristor type converters, and the first and first switching circuits may also be configured as thyristor type switching devices.The conventional device is configured as described above. If the excitation function of the SG coil was lost while the control rods were on standby, the control rod drive shaft could not be held, causing the control rods to fall, potentially resulting in reactor shutdown. This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and when the excitation mechanism of the SG coil is lost, the M0 coil is excited by the control of a newly installed failure detection section. It is an object of the present invention to provide a device capable of holding control rods.In order to achieve this object, a nuclear reactor control rod control device according to the present invention includes a plurality of predetermined groups of lift coils; A seventh switching circuit that sequentially selects one group of lift coils from a plurality of groups in a predetermined sequence: converts the three-phase power supply to a DC current at a level based on the first reference current signal of a reference current source that sequentially generates a plurality of reference levels. Convert this to the first
A first electric crab unit that supplies movable gripper coils to a group of lift coils via a switching circuit: movable gripper coils in the same number of groups as the predetermined plurality of groups; All switching circuit; a first converting the three-phase power supply into a direct current at a level based on a second reference current signal of the reference current source, and supplying this to a group of movable gripper coils via the second switching circuit; Power unit: the same number of stationary gripper coils as the predetermined plurality of groups; and a power unit provided corresponding to each of the predetermined plurality of groups of stationary gripper coils, which supplies the three-phase power source with the predetermined sequence from the reference current source. @3 electric crab units; converting the DC currents into DC currents each having a level based on a separate third reference current signal group and supplying the DC currents to the stationary gripper coils of the predetermined plurality of groups; ．． Second
Insertion/extraction operations of the two groups of control rods are performed via each of the above-mentioned type crab units based on the third reference current signal, and the third reference current signal group other than the insertion/extraction operation is applied to the third reference current signal group other than the insertion/extraction operation. In the reactor control rod control system which energizes the stationary gripper coil through a 37 electric power unit: It is connected to the input terminal of the second switching circuit, and when there is a failure in which a DC output signal is not generated from the stem of the third crab knit, the kneading is detected and the stationary gripper coil of the group corresponding to the faulty crab knit is connected. The second switching circuit is selectively controlled so that the movable gripper coils of the same group are excited, and at the same time, the first reference current signal is disabled so that a predetermined DC holding current is supplied from the second electric current. The present invention is characterized in that it includes a failure detection section that forcibly controls energization of the second double crab knit. The present invention will be explained below with reference to embodiments shown in the accompanying drawings. The point in FIG. 4 that is similar to FIG. ;0.32 and the output point of tll? 2゜91I and?
The failure detection section θ is connected to the third power unit θ and the first switching circuit 7, and the current value signals from these are input. When it is detected that there is an abnormality in the output current of the output current, for example, no current flows, regardless of the second reference current signal from the reference current source 4.2 to the third power unit θ,
That is, in order to invalidate the second reference signal, a command signal is issued to supply a predetermined DC holding current to the second set of loads 20 via the line 9g. At the same time, the line lθθ
A command signal is issued to energize the load of the group (/) corresponding to the group to which the abnormal third electric circuit belongs. In this system, the control rod insertion/extraction function is no different from the conventional system, but if the excitation function of the SG coil holding the control rod is lost, this is detected and the second heavy crab unit l It has a unique function of preventing the control rod from falling by energizing the M() coil by B. For example, if the third electric crab unit SO fails and the current necessary to hold the control rods is no longer supplied to the first group load (S() coil) saw of the first group IO, an abnormality in this current Output point of absence? The failure detection unit detects the
The second switching circuit 7A selects the load (MC) coil 22 of the first group of the second set 2θ based on the signal from the failure detection unit deθ on the line lθθ. On the other hand, the second electric capacitor lI6 is instructed to supply a DC holding current by the signal 9g from the failure detection section θ. Therefore, the 3rd electric carinitsu t
Even if the stationary latch (Fig. 7) of the first group attempts to open due to failure of the
The two MG coils in the group are energized (1A) and the movable latch in the first group closes to grip the control rod drive shaft, so the control rod is held in a fixed position without falling. The above example deals with a case where a failure occurs in the third electric cylinder go, but it goes without saying that even if a failure occurs in the third electric cylinder 32 or Tada, the control rods are held in the same way. As described above, according to the present invention, the first set of loads lθ(Sa
The structure is such that the abnormality in the current supplied to the microcoil is monitored, and if there is an abnormality, the load (MG coil) of the nuclear group with the abnormality among the second set of loads is energized from the second electric crab unit.
This has the effect of preventing unnecessary control rods from falling and preventing unplanned reactor shutdowns.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of the control rod drive mechanism in a nuclear reactor.
FIG. 2 (at and (b3) are diagrams showing the operation sequence of the control rod drive mechanism, FIG. 3 is a block diagram of a conventional nuclear reactor control rod control device, and FIG. 4 is a nuclear reactor according to an embodiment of the present invention. This is a block diagram of the control rod control device. In the figure, lθ is the first set of loads (SG coil), 20 is the second set of loads (MG coil), 3θ is the third set of load lifts,
θ is the three-phase power supply, Guko is the first power supply, 41A is the first and second power supply, Ri θ, Tacho and tag are the third power supply, 6λ is the reference current source, AA is the seventh switching circuit, and 76 is the Second switching circuit, /co. , I and 32 are the first group loads, /II, , 2'l and 3
'1 is the second group load, /A, col and ? 6 is a third group load, and 90 is a failure detection section. In the drawings, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno - (19) Ku -

Claims (1)

[Claims] A predetermined plurality of groups of lift coils; a first switching circuit that sequentially selects one group of lift coils from the predetermined plurality of groups in a predetermined sequence; a standard that sequentially generates a plurality of reference levels from a three-phase power supply; A first electric crab unit that converts into a DC current at a level based on the first reference current signal of the current source and supplies it to a group of lift coils via the first switching circuit: A number of groups to the same as the predetermined plurality of groups. movable grip coil: a second switching circuit that sequentially selects one group of movable gripper coils from the predetermined plurality of groups in the predetermined sequence; The first electric crab unit converts the direct current into a direct current and supplies this to a group of movable gripper coils via the second switching circuit:
stationary gripper coils in the same number of groups as the predetermined plurality of groups; and stationary gripper coils provided corresponding to the predetermined plurality of groups, respectively, to connect the three-phase power source to the predetermined sequence from the reference current source. a third electrical unit that converts the DC current into a DC current having a level based on each separate third reference current signal group and supplies the DC current to each of the predetermined plurality of groups of stationary gripper coils; l'I and the third reference current signal, a group of control rods is inserted/withdrawn through each of the above-mentioned type crab units, and the third reference current signal group outside of the insertion/withdrawal operation is In a nuclear reactor control rod control device that energizes the stationary gripper coil via the third electric crab unit: an output terminal of each of the third electric crab units, an input terminal of the second electric crab unit, and the second switch. When a DC output signal is not generated from the chair of the third electric crab unit connected to the input terminal of the circuit, this is detected and the stationary gripper coil of the group corresponding to the faulty crab unit is connected to the stationary gripper coil of the same group. When the movable gripper coil is energized, the second switching circuit is selectively controlled, and at the same time, the second switch button is pressed to disable the second reference current signal so that a predetermined DC holding current is supplied from the first electric crab unit. , a nuclear reactor control rod control device comprising a failure detection section for forcibly controlling energization of a 2i crab unit.